Method for erecting a reinforced concrete building

ABSTRACT

A reinforced concrete superstructure is erected from three principal types of prefabricated elements: (1) rectangular floor slabs, (2) rectangular wall panels, and (3) box units comprising integrally poured vertical walls, preferably integral with a ceiling or floor and having openings through the vertical walls to provide doors and windows and also passages through these or the floor or ceiling for conduits and piping. Typical box units comprise two bathrooms in back-to-back arrangement or two kitchens similarly arranged, but there are other types. The boxes are vertically stacked and, typically, at each level they are erected before the other walls are erected so that they serve as the bracing system for the erection of a keyed construction. Reinforcing rods in the various units are arranged so that they can be structurally joined to each other by simple grouting operation after being set in place.

United States Patent 1 1 Yang et a1.

[ May 28, 1974 METHOD FOR ERECTING A REINFORCED CONCRETE BUILDING [22] Filed: Jan. 3, 1972 [21] Appl. No.: 214,647

[52] US. Cl 52/745, 52/79, 52/236, 52/259 [51] Int. Cl E04g 21/00 [58] Field of Search 52/79, 236, 259, 234, 745

[56] References Cited UNITED STATES PATENTS 1,886,962 11/1932 La Roche 52/79 2,168,725 8/1939 3,162,863 12/1964 Wokas 3,292,327 12/1966 Van Der Lely 3,510,997 5/1970 Ratych 52/236 3,694,973 10/1972 Unger 52/236 3,710,534 1/1973 McNamara.., 52/236 FOREIGN PATENTS OR APPLICATIONS 658,482 5/1965 Belgium 52/79 1,425,370 12/1965 France 52/79 865,652 7/1949 Germany 52/79 1,158,708 7/1969 Great Britain 52/79 Switzerland 52/236 Switzerland 52/236 Primary Examiner-John E. Murtagh Attorney, Agent, or Firm-Owen, Wickersham &

Erickson [5 7 ABSTRACT rangement or two kitchens similarly arranged, but

there are other types. The boxes are vertically stacked and, typically, at each level they are erected before the other walls are erected so that they serve as the bracing system for the erection of a keyed construction. Reinforcing rods in the various units are arranged so that they can be structurally joined to each other by simple grouting operation after being set in place.

13 Claims, 21 Drawing Figures PATENTEDMY 28 M4 FIG..2

FATENTEDHAY28 1914 $812,637

SHEET 7 BF 7 METHOD FOR ERECTING A REINFORCED CONCRETE BUILDING BACKGROUND OF THE INVENTION This invention relates to an improved method for erecting reinforced concrete buildings, using a few types of prefabricated elements which can be brought to various degrees of completion before erection and can be erected simply and at relatively low cost in a manner which affords a very strong construction resistant to seismic shocks and other lateral forces, including wind.

The high cost of building construction is well known, and many attempts have been made to do something about it. So far as relatively high-rise buildings are concerned, it has been difficult to improve upon the typical girder construction with poured-in-place concrete. Life-slab structures have been used in many instances, and other attempts at prefabricating some or part of the buildings have been made. Heretofore, prefabrication seems to have been at its best for the facing of the building, while the floors and. partition walls of the buildings have been erected in place, with everything depending usually upon the steel girder frame. Reinforced concrete buildings without girder frames have also been built, and by the use of prestressed concrete have been able to reach considerable heights too. Even so, the cost differentiation has not been sufficient, and there has remained a considerable demand for buildings that could be more nearly mass-produced.

The present invention is important in the construction not only of high-rise buildings but also of lower multistory structures. It can be used for the construction of office buildings, but a prime place where the skills are particularly needed is in the building of dwelling units such as apartments, condominiums, hotels, and similar types of multifamily unit buildings. Typically, these have been characterized by high cost, and Federal housing, even for poor families, has been achieved only at considerable expense, usually never recoverable from the occupants. Similarly, higher-rent buildings have required very high rents in order to re- SUMMARY OF THE INVENTION When the foundation has been poured and, at the time of pouring, provided with upwardly-projecting reinforcing rods, a lowest floor is placed on top. This may often be most conveniently poured in place according to standard current procedure. Alternatively, a slab base may be erected from a series of rectangular floor slab members, each having a substantially constant thickness except adjacent their edges, where they are tapered. In each floor slab, reinforcing rods project from the edges. During erection these reinforcing rods are placed adjacent other reinforcing rods and are united later into the same structure by grout.

Upon this foundation box units are erected. Some of these box units may be two kitchens located back to back, and some may be two bathrooms located back to back; some of them may be single kitchens or bathrooms; others may be stairwell units or elevator-shaft units or other vertical shaft units, or still other structural units. Most of these box units comprise an integrally poured side wall and ceiling (or floor) configuration, with openings through the walls to provide doors and windows and openings through the ceiling to provide passages for conduits and piping. In other words,

the ceiling or floor comprises a horizontal wall that joins the side walls and is integral with them. Elevator and other vertical shafts and stairwell units do not, of course, have ceilings or floors. The ceiling has recesses at intervals, and the side walls and ceiling both have vertical reinforcing rods projecting into the recesses and also below the lower ends of the side walls. Some of'the walls are provided with vertical keyed projections, preferably V-shaped, and the ceiling is set back from the edges to provide ledges at the top of the side walls. When these box units are erected, the reinforcing rods that project from the lower end project close to the rods of the foundation and-to rods in the adjacent floor. Grouting is then provided to unite these reinforcing rods, so that the floor, foundation, and box units are all tied together permanently.

In the next stage of construction, wall panels are placed on the lowest floor. The wall panels are rectangular with vertically extending reinforcing rods that project both above and below their top and bottom edges, and they have some side edges provided with V- shaped indentations to key into the key projections of the box unit. The, placing of the wall panel includes keying some of them to the box unit, and their reinforcing rods lie close to those of the floor at the bottom and top. The wall panels, floor, and foundations are grouted together to complete the erection at this stage.

Going on from this bottom story, the next story is started by placing a box unit over each of the box units of the first level and grouting them together. Floor slabs are then placed on the wall panels and on the ledges of the box units, and their reinforcing rods are structurally tied into the reinforcing rods of those units by grouting.

After that, wall panels are erected as before and grouted as before'and from story to story the structural procedure then remains substantially the same, first erecting the box units over lower box units, then placing the floor slabs, and then erecting wall panels to support the succeeding story.

The vertical stacking of the box units and their attachment by unique types of connections form a series of tower-like structures that are resistant to such lateral forces as earthquake and wind. Thus the box units may be spaced throughout an otherwise free plan to provide key parts of the buildings skeleton. The box units carry the vertical load as well as the lateral load of the building, with the aid of the interlocking connections. The rigidity of the box units is'increased when their walls are poured substantially monolithically .with their ceiling or floor, thereby increasing .the rigidity of the unit for easy handling. Since the box units are erected before the other walls are erected, they serve as the bracing system for the erection employing the keyed connections. It also makes it possible to install the fixtures in the plant, where more efficient and relatively lowercost laborers can be used, making it relatively simple to connect the plumbing and drainage systems on the site.

Some of the electrical work can also be done at the factory.

The kitchen and bathroom units can be arranged, if necessary, to satisfy all kinds of apartment layouts and studio types and multibedroom types and also other related housing programs, such as hotels, motels, dormitories, barracks, and so on. I

The novel interconnection of the wall-to-wall, wallto-slab sIab-to-wall and sIab-and-wall-to-box are also very noteworthy and of considerable importance. The keyed connections between the walls of the box units and the wall panels are also an important part.

All the precast elements may -be tailored to sizes which can be transported on the highways and to weights which can be handled with medium-sized erection equipment, again increasing efficiency while lowering costs. If site precasting is feasible,-the sizes of the floor slabs may be increased to one piece for a wholeroom, in order to reduce the number of connections. In other words, slabs and panels can often conveniently be built right at the site, and if that is so, they need not be' as smallas they would have to be for highway transportation.

Other objects and advantages of the invention will appear'from thefollowing description of a preferred embodiment thereof.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is an isometric view, with parts broken away,

. of a partially-constructed apartment building embodying the principles of the invention.

FIG. 2 is a representative floor plan of a partially constructed apartment building embodying the principles of the invention. 3 I

FIG. 3 is a top plan view of one of the box units of the invention, also showing the location of the reinforcing rods in somewhat diagrammatic form. It may be considered as taken along the line 3-3 in FIG. 5, but enlarged.

FIG. 4 is a view in section generallysimilar to FIG. 3 but taken at a point approximately midway the height of the box unit, along the line 44 in FIG. 5.

FIG. 5 is a view in section on a reduced scale taken along theline 55 in FIG. 3.

FIG. 6 is an enlarged fragmentary view in section taken along the line 66 in FIG. 3 prior to grouting, showing, in addition, parts of an adjacent floor slab, two adjacent wall panels, and an adjacent box unit.

FIG. 7 is an enlarged fragmentary view in section taken along the line 7-7 in FIG. 3 prior to grouting, showing, in addition, parts of an adjacent floor slab and an adjacent box unit. I

FIG. 8 is an enlarged fragmentary view in section taken along theline8-8 in FIG. 3 prior to grouting, showing parts of an adjacent box unit and an adjacent floor slab.

FIG. 9 is an enlarged fragmentary view in section taken along the line 99 in FIG. 3 prior to grouting, showing part of an adjacent floor slab.

FIG. 10 is a somewhat enlarged fragmentary view in section taken along the line l0-10 in FIG. 5, showing part of an adjacent wall panel. I

FIG. 11 is an enlarged fragmentary plan view at. a place where awall panel meets a box unit ata keyed connection.

FIG. 12 is a fragmentary view in section taken along the line l212'in FIG. 11.

FIG. 13 is an enlarged fragmentary view in elevation and in section of the juncture of two box units and some floor slabs, taken at l3l3 in FIG. 3 showing the construction including the reinforcing and the groutin FIG. 14 is a top plan view or view in section taken along the line 14-l4 in FIG. 13 prior to the adding of the grout.

FIG. 15 is a view in elevation and in section of a modified form of box unit having an integrally attached cantilever slab and shown with parts of adjacent slab and box units.

FIG. 16 is a fragmentary top plan view of the box unit of FIG. 15.

FIG. 17 is an enlarged view in elevation and in section taken along the line l7l7 in FIG. 16 and which comprises a view in section showing the juncture of the cantilevered slab to an adjacent floor-slab, together with the grouting.

FIG. 18 is an enlarged fragmentary view in section taken along the line I8l8 in FIG. 16 showing a portion of. the box unit thereabove.

FIG. 19 is an enlarged fragmentary view in section taken along the line I9-I9 in FIG. 16 prior to grounting and showing a portion of the box unit thereabove.

FIG. 20 is an isometric view partly broken away showing a modified form box unit, with the floor (instead of the ceiling) integral with the walls, and comprising two. bathrooms-back to back with the fixtures installed before installation. I

FIG. 21 is a view in elevation and in section taken along the line 21 2l in FIG. 20 and showing in somewhatdiagrammatic manner aninstalled box unit of FIG. 20 resting on the floor below.

DESCRIPTION OF A PREFERRED EMBODIMENT FIG. 1, an isometric view, gives some idea of how the method of this invention is practiced, that is, how the building looks during a stage at its erection, while FIG.

2 gives the completed floor plan for one floor. FIG. 2 shows six box units 31, 32, 33, 34, 35, and 36,.of which the units 32 and 34 are identical, as are the box units 33 and 35. The units 33, 34, and 35 are shown in FIG. 1. The box units 32 and 34 may be two bathrooms placed back to back without any partition wall being shown in these views, but with partition walls being erected either before or during construction .of the building, depending on which is more economical. Similarly, the box units 33 and 35 may be two kitchens placed back to back. The box unit 31 may be a singlekitchen unit, and the box unit 36 may be a singlej bathroom unit. In other buildings, there may be other kinds of box units, such as stairwells, with integrally poured stairs and landings, and elevator and other vertical shafts having no ceiling or floor, but otherwise similar and similarly treated and located at proper locations. Then box units may be located adjacent to a double-loaded corridor, if desired, or elsewhere, depending 47 and 48. It may be convenient in some structures for all the floor slabs to be the same size and for all the wall panels to be the same size, or it may be that some variety will be helpful in use. For example, there may be differences between inside and outside walls or for particular slab locations, as for example, some of the floor slab units may comprise the floor for a whole room, as shown by the slabs 41 and 43 in FIG. 2, with the rooms being in this view shown in two different sizes, while the floor slab 42 between adjacent box units may be of third size. However, the invention contemplates the use of a standard floor slab structure and a standard wall panel structure, even though there may be several sizes or types of each. Some wall panels, for example, can be provided with windows for use in outside walls, some of them may be completely solid, some may have doors, some of them may have openings for conduits, and so on.

So far as the present invention is concerned, however, all of the wall panels 41, 42, 43, 44 are basically alike, all being flat members of uniform thickness, all having reinforcing rods 50 which run in at least one direction, preferably in two directions, widthwise and lengthwise, and the ends of the reinforcing rods 50 project from them at sloped or beveled edges 51 (see FIGS. 6-9 and 17). Similarly, all the wall panels are basically alike, with reinforcing rods 52 running vertically and horizontally. Some or all of the side edges of the wall panels may have key-shaped recesses 53 for better juncture with adjacent keyed members (see FIGS. and 11). The wall panels 48 have doors 55 therethrough.

The box units are of particular importance. The box units 33 and 35 are devised as two kitchens located back-to-back; the box units 32 and 34 each comprise a pair of bathrooms back-to-back; the box unit 31 is a single kitchenette, and the box unit 36 is a single bathroom. Box units may also serve as stairwells, elevator shafts, storage rooms, and so on, as-stated. However, all the box units share certain important features in common. Thus, in all of them four vertical walls, shown in FIGS. 3-5 as the walls 60, 61, 62, and 63 are poured monolithically, and in all but the elevator and other vertical shafts and stairwells, they are poured monolithically with one horizontal slab, which may be a floor (FIGS. and 21) or the ceiling 64 (FIGS. 3, 5, etc.), which also serves as the floor of the box unit next above. The walls and ceiling are all provided with reinforcing rods 66 running in one or both directions. The walls 61 and 63 have door openings 67 and 68 respectively, and openings 69 in the ceiling 64 are provided as shown in FIG. 3 to enable the installation of pipes, conduits, and so on.

As may be seen in FIGS. 6-9, among others, the ceiling 64 is set back from the outer edges of the walls 60, 61, 62, 63 to provide a ledge 70 upon which floor slabs 41, 42, 43 may be placed during construction. This is a very important feature of the invention, along with the provision of grouting openings 71 at intervals, each cooperating with a tapered edge 51 of a slab 41, 42, or 43, to enable introduction of grout 72 to tie all the reinforcing rods 50, 66, etc., there together. Note that the ledge 70 varies considerably in width in order to achieve this. The reinforcing rods that project from the slabs, walls, and box unitscan thus be combined with the grout 72 to unite the whole structure. FIGS. 6-9, where the grout 72 is omitted, show how this is done.

FIG. 7 shows the support of the slabs 41 at the time of erection and before grouting.

FIG. 9 also shows a floor slab 42 rests on the ledge on top of a box unit. FIGS. 6-8 show how one box unit rests on top of another, with an adjacent slab 41 or 42 or 43 on a ledge 70. The rods 66 from the lower box project up and the reinforcing rods 66 for the upper box project down. These rods 66 may be of various shapes, with U-shaped rods being shown in FIGS. 6 and 8 and an L-shaped pattern shown in FIG. 7. Into the recesses the grout 72 is later poured.

FIGS. 11 and 12 show how a wall panel 45 is secured to a box unit 33. The keying recess 53 of the panel 45 is keyed to the projections 73 on the box unit 33, both these keys being shown as triangular, though they may be some other shape. Tie rods 74 and 75 tie the rods 52 that project from the wall panel 45 to the reinforcing rods 66 that project from the wall 60 of the box unit 33. The recesses 70 are then filled with grout to tie the two wall panels 45 to each other and to the two box unit walls 60.

At the corners of the box units, special structures are preferably employed, as shown in FIGS. 13 and 14. Here high-strength rods and 81 with their ends threaded, project up from the bottom box unit 33, and similar rods 82 and 83 project down from the upper box unit 33 and they are located as shown in FIGS. 13 and 14, so that a steel plate 84 may be used and the threaded connections made with the aid of nuts 85. The rods 80 and 81 projecting up from the upper end define one diagonal line, and the rods 82 and 83 from the lower end define another diagonal line, to make the structure shown in plan in FIG. 14. This gives especially great strength here. When grout 87 fills the recess 86 the structure is quite stable.

A modified form of box unit 90 is shown in FIGS. 15-17, having four walls, three walls 91, 92, 93 of which are shown, monolithic with a ceiling 94, which again has a ledge 70 along its edges. In addition, the ceiling 94 is continuous with a cantilevered slab 95, forming part of the floor and linked to a regular floor slab or to a similar cantilevered slab of an adjacent box unit as shown in FIG. 17, which also illustrates the normal manner of joining adjacent slabs.

Another modified form of box unit is shown in FIGS. 20 and 21, comprising two bathrooms placed back to back and substantially finished before installation. In this unit 100, four main walls 101, 102, 103 and 104 are monolithically poured with a floor 105. The individual bathrooms are closed off by partitions 106 and 107, which may be installed at the plant and define between them a passage area 108 for pipes and conduits. Fixtures such as a tub-shower unit 110, a toilet 11, a washstand 112, etc., are fully installed before placement.

In erecting the building of FIGS. 1 and 2, the building is started by pouring a foundation having upwardly projecting reinforcing rods. Upon the foundation a floor may be poured in place, according to conventional practice. Alternatively, a floor slab base may be erected by placing the floor slabs 41, 42, 43, and 44 across at locations provided for in the foundation, so that their reinforcing rods 50 touch or are connected to those of the foundation. On this floor,each of the box units 31, 32, 33, 34, 35 and 36 is erected, with the reinforcing rods 82 and 83 that project from their lower ends being interconnected with reinforcing rods 80 and 81 of the foundation, in the same manner as that shown in FIGS. 13 and 14, providing very strong points at the corners. In addition, the projecting portions of other reinforcing rods 66 are placed adjacent rods projecting up from the foundation and adjacent the rods 50 on the floor slabs, so that all can be tied together by grout 72. When the grouting is completed, the box units 31, 32, 33, 34, 35, and 36 are completely installed, and the floor is solidly in place. The wall panels 45, 46, 47 and 48 for this particular story are erected and are keyed to the box units and also to the foundation and to the floor. Connections are made by means of locating the reinforcing members near together, and then when these are grouted, the lower portion of the first story is completed. v I

The next story is begun by installing another box'unit on top of each of the already-installed box units, and the reinforcing rods are aligned, and bolting is carried on at each of the four corners. When this has been done, floor slabs 41, 42, 43, and 44 are set in place, and then the upper floor slabs and, upper and lower box units are grouted together. More wall units 45, 46, 47, and 48 are erected as before'on top of the upper slab units and keyed into the upper box units, and are grouted to the floor units and to the box units-at their bottom edge. The construction for each story continues in this manner, with the box units installed first, then the floor slabs then the wall panels. In each instance the grouting is important because it provides the tying together of the entire structure. A high-strength nonshrinking grout is to be used for'all this grouting work, but is is relatively easy to place, since openings for it have been located in all of the slabs.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will.

. suggest themselves without departing from the spirit and scope of the invention. The disclosures and the. description herein are purely illustrative and are not intended to be in any sense limiting.

We claim: 7 v l. A method forerecting a multi-s tory building comprising stacking a plurality of identical-area prefabricated box units in vertical alignment with each other with the stacks spaced apart from each other throughout an otherwise free plan, said box units enclosing an area small in proportion to the total area of the plan, using the stacks as cores for supporting the walls and floors of the building by erecting prefabricated wallpanels and floor slabs in areas between said stacks, the box units, slabs, and panels. containing reinforcing meansthat project therefrom, and grouting the projecting reinforcing means together to tie together, said reinforcing means, box units, slabs, and panels.

2. A method for erecting a multi-story reinforced concrete building over a first floor, from prefabricated 3. superimposing a box unit directly over each said box unit in vertical alignment with reinforcing rod means closely adjacent,

4. placing floor slabs on said wall-panels and on ledges on the upper edges of said box units, with reinforcing rod means located close to those of said box units or of other floor slabs,

5. grouting together the reinforcing rod means of superimposed box units, floor slabs, and wall panels, and r 6. continuing the erection by, at each level, following steps (2), (3), and (4).

3. The method of claim 1 including the step of preparing at least some box units in advance as rooms or room' groups with an integral floor-ceiling member in each.

4. A method for erecting a multi-story reinforced concrete building upon a poured foundation and upon a lowest floor, from prefabricated elements, comprising 5. superimposing a box unit directly over each said box unit in vertical alignment with reinforcing rod means closely adjacent, i v

6.'placing floor .slabs on said wall panels and on ledges on the upper edges of said box units, with reinforcing rod means located close to those of said box units or of other floor slabs,

7. grouting together the reinforcing rod means of superimposed box units and floor slabs,

8. erecting wall slabs as before and grouting as before and 9 continuing the erection by, at each level, following steps (5), (6), (7), and (8) in order. 5. The method of claim 4 wherein said box units comprise integrally poured vertical walls.

6. The method of claim.5 wherein at least some of said box units comprise a ceiling integrally poured with said walls.

7. The method of claim 5 wherein at least some of I said box units comprise a floor integrally poured with said walls.

8. The method of claim 5 wherein said walls include door openings and window openings.

9. The method of claim 5 wherein said side walls include keying means and some of said panels include matching keying means for keying panels to said box units..

10. The method of claim 5 whereinsaid floor'slabs have a substantially constant thickness exc pt adjacent the edges where they are tapered, the reinforcing rod means-projecting from the tapered portions.

IL The method of claim 4 wherein said box units comprise integrally poured side walls with reinforcing and foundations,

rod means projecting from upper-and lower edges, at

12. A method for erecting a multi-story reinforced '0 concrete building upon a poured foundation with upwardly projecting reinforcing rod means and upon a lowest floor, from prefabricated elements, comprising 1. erecting upon said foundation and lowest floor a series of box units spaced apart from each other and each comprising integrally poured walls with reinforcing rod means projecting from upper and lower edges and placed closely adjacent to the rod means of said foundation and with those of said lowest floor, some of said walls having openings therethrough to provide doors, windows, and passages for conduits and piping, said box units having at their upper end ledges for supporting of floor slab members and having grouting openings adjacent projecting reinforcing rod means, some of side walls having vertical V-shaped projections, grouting together the box unit, the floor it rests on, and the foundation, to tie their reinforcing rod means together,

3. Placing on said floor, a series of rectangular wall panel members each having vertically extending reinforcing rod-means projecting below a bottom edge and placed adjacent reinforcing rod means of said floor and foundation, said panel having reinforcing rod means projecting above a top edge, some of said panels having some edges provided with V-shaped indentations keyed to said V-shaped recesses of said box units,

4. grouting together the reinforcing rod means of said wall panels, floor, and foundation,

5. placing a box unit directly over each said box unit in vertical alignment therewith,

6. placing on said wall panels and on said ledges of said box units, rectangular floor slab members having a substantially constant thickness except adjacent the edges where it is tapered, and having reinforcing rod means projecting from the edges,

7. grouting said box units together and to said floor slabs,

8. erecting wall slabs, as before, on said floor slabs and grouting them to said floor slabs, and

9. continuing the erection, at each level, by following steps (5), (6), (7), and (8) in order.

13. The method of claim 12 wherein said box units include threaded rods projecting upwardly and downwardly at the comers, and the step of securing said threaded rods from two superimposed box units at each corner to the same plate by threaded means. 

1. A meThod for erecting a multi-story building comprising stacking a plurality of identical-area prefabricated box units in vertical alignment with each other with the stacks spaced apart from each other throughout an otherwise free plan, said box units enclosing an area small in proportion to the total area of the plan, using the stacks as cores for supporting the walls and floors of the building by erecting prefabricated wall panels and floor slabs in areas between said stacks, the box units, slabs, and panels containing reinforcing means that project therefrom, and grouting the projecting reinforcing means together to tie together, said reinforcing means, box units, slabs, and panels.
 2. grouting together the box unit, the floor it rests on, and the foundation, to tie their reinforcing rod means together,
 2. A method for erecting a multi-story reinforced concrete building over a first floor, from prefabricated elements, comprising
 2. erecting wall panels where desired between box units with reinforcing rod means projecting down and located closely adjacent to those of the floor and foundations,
 2. grouting where said rod means are to tie together the box units, floor, and foundation,
 3. superimposing a box unit directly over each said box unit in vertical alignment with reinforcing rod means closely adjacent,
 3. The method of claim 1 including the step of preparing at least some box units in advance as rooms or room groups with an integral floor-ceiling member in each.
 3. Placing on said floor, a series of rectangular wall panel members each having vertically extending reinforcing rod means projecting below a bottom edge and placed adjacent reinforcing rod means of said floor and foundation, said panel having reinforcing rod means projecting above a top edge, some of said panels having some edges provided with V-shaped indentations keyed to said V-shaped recesses of said box units,
 3. erecting wall panels on said floor with reinforcing rod means projecting down and located closely adjacent to those of the floor and foundations,
 4. grouting together the reinforcing rod means of said wall panels, floor, and foundation,
 4. placing floor slabs on said wall panels and on ledges on the upper edges of said box units, with reinforcing rod means located close to those of said box units or of other floor slabs,
 4. A method for erecting a multi-story reinforced concrete building upon a poured foundation and upon a lowest floor, from prefabricated elements, comprising
 4. grouting the reinforcing rod means of said wall panels, floor, and foundation together,
 5. superimposing a box unit directly over each said box unit in vertical alignment with reinforcing rod means closely adjacent,
 5. The method of claim 4 wherein said box units comprise integrally poured vertical walls.
 5. grouting together the reinforcing rod means of superimposed box units, floor slabs, and wall panels, and
 5. placing a box unit directly over each said box unit in vertical alignment therewith,
 6. placing on said wall panels and on said ledges of said box units, rectangular floor slab members having a substantially constant thickness except adjacent the edges where it is tapered, and having reinforcing rod means projecting from the edges,
 6. The method of claim 5 wherein at least some of said box units comprise a ceiling integrally poured with said walls.
 6. placing floor slabs on said wall panels and on ledges on the upper edges of said box units, with reinforcing rod means located close to those of said box units or of other floor slabs,
 6. continuing the erection by, at each level, following steps (2), (3), and (4).
 7. grouting together the reinforcing rod means of superimposed box units and floor slabs,
 7. grouting said box units together and to said floor slabs,
 7. The method of claim 5 wherein at least some of said box units comprise a floor integrally poured with said walls.
 8. erecting wall slabs, as before, on said floor slabs and grouting them to said floor slabs, and
 8. The method of claim 5 wherein said walls include door openings and window openings.
 8. erecting wall slabs as before and grouting as before and 9 continuing the erection by, at each level, following steps (5), (6), (7), and (8) in order.
 9. The method of claim 5 wherein said side walls include keying means and some of said panels include matching keying means for keying panels to said box units.
 9. continuing the erection, at each level, by following steps (5), (6), (7), and (8) in order.
 10. The method of claim 5 wherein said floor slabs have a substantially constant thickness except Adjacent the edges where they are tapered, the reinforcing rod means projecting from the tapered portions.
 11. The method of claim 4 wherein said box units comprise integrally poured side walls with reinforcing rod means projecting from upper and lower edges, at least some of said box units having a horizontal wall joining the side walls at one edge thereof and integral therewith, some of said walls having openings therethrough to provide doors, windows, and passages for conduits and piping, said box units having at their upper end ledges for support of floor slab members and having at one edge, at least, grouting openings adjacent projecting reinforcing rod means, some of said side walls having vertical V-shaped projections.
 12. A method for erecting a multi-story reinforced concrete building upon a poured foundation with upwardly projecting reinforcing rod means and upon a lowest floor, from prefabricated elements, comprising
 13. The method of claim 12 wherein said box units include threaded rods projecting upwardly and downwardly at the corners, and the step of securing said threaded rods from two superimposed box units at each corner to the same plate by threaded means. 